Figure 5.11 shows how a TDI client can make transport-specific action requests to the underlying TDI driver if that transport defines such extensions to TDI.
Figure 5.11 Requesting Transport-Specific Extensions
A TDI client can send special or proprietary extension requests to a TDI transport driver that defines a set of transport-specific action codes for these operations. These extensions, which can concern an open address, an open connection endpoint, or an open control channel, apply only to the calling client and not to any other TDI transport clients or drivers.
To request such a transport-defined action operation, the client first must open the address, connection endpoint, or control channel, as already described in Section 5.1, Section 5.2, or Section 5.4, respectively. Then, the client can use TdiBuildAction to set up a TDI_ACTION request with a client-supplied buffer containing the transport-defined action code and corresponding action parameter block for the requested operation.